With AirPods Pro 2, Apple has improved the Charging Case by adding a U1 chip for Precision Finding with Find My. This means there is a speaker built into the case that can emit a sound to help you locate it.
However, the speaker also plays an audible chime whenever you start charging the Charging Case. The sound plays whether you connect the case to power via Lightning or place it down on a charging pad. If you find this distracting, here's an easy way to turn it off.
- Connect your AirPods Pro 2 to your iPhone.
- Launch the Settings app.
- Tap the AirPods Pro 2 tab just under your Apple ID.
- Scroll down and toggle off the switch next to Enable Charging Case Sounds.
That's all you need to do. Note that the setting will remain grayed out if the Charging Case is currently connected to power.